Residential greenness during pregnancy and early life and development of asthma up to 27 years of age: The Espoo Cohort Study.

Previous studies have suggested that living close to green spaces has protective health effects, but potential effects on asthma are contradictory. We investigated the association between the amount of greenness in the residential area during pregnancy and early life and development of asthma in the first 27 years of life. The study population included all 2568 members of the Espoo Cohort Study, Finland. We calculated individual-level exposure to green space measured as cumulative Normalized Difference Vegetation Index (cumNDVI in unit-months) within 300 m of the participant's residence during pregnancy and the first two years of life in both spring and summer seasons. The onset of asthma was assessed using information from the baseline and follow-up surveys. Exposure to residential greenness in the spring season during pregnancy was associated with an increased risk of asthma up to 6 years of age, with an adjusted hazard ratio (aHR) of 3.72 (95% confidence interval (CI): 1.11, 12.47) per 1 unit increase in cumNDVI. Increased greenness in the summer during pregnancy associated with asthma up to 6 years, with an aHR of 1.41 (95% CI: 0.85, 2.32). The effect was found to be related to increased greenness particularly during the third trimester of pregnancy, with an aHR of 2.37 (95% CI: 1.36, 4.14) per 1 unit increase of cumNDVI. These associations were weaker at the ages of 12 and 27 years. No association was found between NDVI in the first two years of life and the development of asthma. Our findings provide novel evidence that exposure to greenness during pregnancy increases the risk of developing asthma. The adverse effects were strongest for the prenatal greenness in the spring season and in the third trimester of pregnancy. Both the season and trimester of exposure to greenness are critical in the development of asthma.

Cold Weather and Cardiac Arrest in 4 Seasons: Helsinki, Finland, 1997‒2018.

Objectives. To test the a priori hypothesis that out-of-hospital cardiac arrest (OHCA) is associated with cold weather during all seasons, not only during the winter. Methods. We applied a case‒crossover design to all cases of nontraumatic OHCA in Helsinki, Finland, over 22 years: 1997 to 2018. We statistically defined cold weather for each case and season, and applied conditional logistic regression with 2 complementary models a priori according to the season of death. Results. There was an association between cold weather and OHCA during all seasons, not only during the winter. Each additional cold day increased the odds of OHCA by 7% (95% confidence interval [CI] = 4%, 10%), with similar strength of association during the autumn (6%; 95% CI = 0%, 12%), winter (6%; 95% CI = 1%, 12%), spring (8%; 95% CI = 2%, 14%), and summer (7%; 95% CI = 0%, 15%). Conclusions. Cold weather, defined according to season, increased the odds of OHCA during all seasons in similar quantity. Public Health Implications. Early warning systems and cold weather plans focus implicitly on the winter season. This may lead to incomplete measures in reducing excess mortality related to cold weather. (Am J Public Health. 2022;112(1):107-115. https://doi.org/10.2105/AJPH.2021.306549).

Association of travel time with mental health service use in primary health care according to contact type - a register-based study in Kainuu, Finland.

BACKGROUND: The study aim was to analyse how mental health services are used in different parts of the Kainuu region in Finland and whether travel time to primary health care services is associated with the use of different contact types (in-person visits, remote contacts, home visits). METHODS: The study population included adults who had used mental health services under primary health care (N = 7643) between 2015 and 2019. The travel times to the nearest health centre in a municipality were estimated as the population-weighted average drive time in postal code areas. The Kruskal-Wallis test and pairwise comparisons with Dunn-Bonferroni post hoc tests were used to assess the differences in mental health service use between health centre areas. A negative binomial regression was performed for the travel time categories using different contact types of mental health service use as outcomes. Models were adjusted for gender, age, number of mental health diseases and the nearest health centre in the municipality. RESULTS: Distance was negatively associated with mental health service use in health centre in-person visits and in home visits. In the adjusted models, there were 36% fewer in-person visits and 83% fewer home visits in distances further than 30 min, and 67% fewer home visits in a travel time distance of 15-30 min compared with 15 min travel time distance from a health centre. In the adjusted model, in remote contacts, the incidence rate ratios increased with distance, but the association was not statistically significant. CONCLUSIONS: The present study revealed significant differences in mental health service use in relation to travel time and contact type, indicating possible problems in providing services to distant areas. Long travel times can pose a barrier, especially for home care and in-person visits. Remote contacts may partly compensate for the barrier effects of long travel times in mental health services. Especially with conditions that call for the continuation and regularity of care, enabling factors, such as travel time, may be important.

Individual and Area-level Factors Contributing to the Geographic Variation in Ambulatory Care Sensitive Conditions in Finland: A Register-based Study.

BACKGROUND: Measuring primary health care (PHC) performance through hospitalizations for ambulatory care sensitive conditions (ACSCs) remains controversial-recent cross-sectional research claims that its geographic variation associates more with individual socioeconomic position (SEP) and health status than PHC supply. OBJECTIVES: To clarify the usage of ACSCs as a PHC performance indicator by quantifying how disease burden, both PHC and hospital supply and spatial access contribute over time to geographic variation in Finland when individual SEP and comorbidities were adjusted for. METHODS: The Finnish Care Register for Health Care provided hospitalizations for ACSCs (divided further into subgroups of acute, chronic, and vaccine-preventable causes) in 2011-2017. With 3-level nested multilevel Poisson models-individuals, PHC authorities, and hospital authorities-we estimated the proportion of the variance in ACSCs explained by selected factors at 3 time periods. RESULTS: In age-adjusted and sex-adjusted analysis of total ACSCs the variances between hospital authorities was nearly twice that between PHC authorities. Individual SEP and comorbidities explained 19%-30% of the variance between PHC authorities and 25%-36% between hospital authorities; and area-level disease burden and arrangement and usage of hospital care a further 14%-16% and 32%-33%-evening out the unexplained variances between PHC and hospital authorities. CONCLUSIONS: Alongside individual factors, areas' disease burden and factors related to hospital care explained the excess variances in ACSCs captured by hospital authorities. Our consistent findings over time suggest that the local strain on health care and the regional arrangement of hospital services affect ACSCs-necessitating caution when comparing areas' PHC performance through ACSCs.

Short-term prenatal exposure to ambient air pollution and risk of preterm birth - A population-based cohort study in Finland.

BACKGROUND: Previous studies have provided evidence that prenatal exposure to low-level air pollution increases the risk of preterm birth (PTB), but the findings of the effects of short-term exposure have been inconclusive. Moreover, there is little knowledge on potential synergistic effects of different combinations of air pollutants. OBJECTIVES: To assess independent and joint effects of prenatal exposure to air pollutants during the week prior to the delivery on the risk of PTB. METHODS: The study population included 2568 members of the Espoo Cohort Study, living in the City of Espoo, Finland, born between 1984 and 1990. We assessed individual-level prenatal exposure to ambient air pollutants of interest based on maternal residential addresses, while taking into account their residential mobility. We used both regional-to-city-scale dispersion modelling and land-use regression-based method to estimates the pollutant concentrations. We contrasted the risk of PTB in the highest quartile (Q4) of exposure to the lower exposure quartiles (Q1-Q3) during the specific periods of pregnancy. We applied Poisson regression analysis to estimate the adjusted risk ratios (RRs) with their 95% confidence intervals (CI), adjusting for season of birth, maternal age, sex of the baby, family's socioeconomic status, maternal smoking, and exposure to environmental tobacco smoke during pregnancy, single parenthood, and exposure to other air pollutants (this in multi-pollutant models). RESULTS: The risk of PTB was related to exposures to PM2.5, PM10 and NO2 during the week prior to the delivery with adjusted RRs of 1.67 (95%CI: 1.14, 2.46), 1.60 (95% CI: 1.09, 2.34) and 1.65 (95% CI: 1.14, 2.37), from three-pollutant models respectively. There were no significant joint effects for these different air pollutants (during the week prior to the delivery). CONCLUSION: Our results provide evidence that exposure to fairly low-level air pollution may trigger PTB, but synergistic effects of different pollutants are not likely.

Effect of centralization on geographic accessibility of maternity hospitals in Finland.

BACKGROUND: In the past two decades, the number of maternity hospitals in Finland has been reduced from 42 to 22. Notwithstanding the benefits of centralization for larger units in terms of increased safety, the closures will inevitably impair geographical accessibility of services. METHODS: This study aimed to employ a set of location-allocation methods to assess the potential impact on accessibility, should the number of maternity hospitals be reduced from 22 to 16. Accurate population grid data combined with road network and hospital facilities data is analyzed with three different location-allocation methods: straight, sequential and capacitated p-median. RESULTS: Depending on the method used to assess the impact of further reduction in the number of maternity hospitals, 0.6 to 2.7% of mothers would have more than a two-hour travel time to the nearest maternity hospital, while the corresponding figure is 0.5 in the current situation. The analyses highlight the areas where the number of births is low, but a maternity hospital is still important in terms of accessibility, and the areas where even one unit would be enough to take care of a considerable volume of births. CONCLUSIONS: Even if the reduction in the number of hospitals might not drastically harm accessibility at the level of the entire population, considerable changes in accessibility can occur for clients living close to a maternity hospital facing closure. As different location-allocation analyses can result in different configurations of hospitals, decision-makers should be aware of their differences to ensure adequate accessibility for clients, especially in remote, sparsely populated areas.

Synergistic effects of prenatal exposure to fine particulate matter (PM2.5) and ozone (O3) on the risk of preterm birth: A population-based cohort study.

BACKGROUND: There is some evidence that prenatal exposure to low-level air pollution increases the risk of preterm birth (PTB), but little is known about synergistic effects of different pollutants. OBJECTIVES: We assessed the independent and joint effects of prenatal exposure to air pollution during the entire duration of pregnancy. METHODS: The study population consisted of the 2568 members of the Espoo Cohort Study, born between 1984 and 1990, and living in the City of Espoo, Finland. We assessed individual-level prenatal exposure to ambient air pollutants of interest at all the residential addresses from conception to birth. The pollutant concentrations were estimated both by using regional-to-city-scale dispersion modelling and land-use regression-based method. We applied Poisson regression analysis to estimate the adjusted risk ratios (RRs) with their 95% confidence intervals (CI) by comparing the risk of PTB among babies with the highest quartile (Q4) of exposure during the entire duration of pregnancy with those with the lower exposure quartiles (Q1-Q3). We adjusted for season of birth, maternal age, sex of the baby, family's socioeconomic status, maternal smoking during pregnancy, maternal exposure to environmental tobacco smoke during pregnancy, single parenthood, and exposure to other air pollutants (only in multi-pollutant models) in the analysis. RESULTS: In a multi-pollutant model estimating the effects of exposure during entire pregnancy, the adjusted RR was 1.37 (95% CI: 0.85, 2.23) for PM2.5 and 1.64 (95% CI: 1.15, 2.35) for O3. The joint effect of PM2.5 and O3 was substantially higher, an adjusted RR of 3.63 (95% CI: 2.16, 6.10), than what would have been expected from their independent effects (0.99 for PM2.5 and 1.34 for O3). The relative risk due to interaction (RERI) was 2.30 (95% CI: 0.95, 4.57). DISCUSSION: Our results strengthen the evidence that exposure to fairly low-level air pollution during pregnancy increases the risk of PTB. We provide novel observations indicating that individual air pollutants such as PM2.5 and O3 may act synergistically potentiating each other's adverse effects.

Inferring the effects of potential dispersal routes on the metacommunity structure of stream insects: as the crow flies, as the fish swims or as the fox runs?

1. Metacommunity research relies largely on proxies for inferring the effect of dispersal on local community structure. Overland and watercourse distances have been typically used as such proxies. A good proxy for dispersal should, however, take into account more complex landscape features that can affect an organism's movement and dispersal. The cost distance approach does just that, allowing determining the path of least resistance across a landscape. 2. Here, we examined the distance decay of assemblage similarity within a subarctic stream insect metacommunity. We tested whether overland, watercourse and cumulative cost distances performed differently as correlates of dissimilarity in assemblage composition between sites. We also investigated the effect of body size and dispersal mode on metacommunity organization. 3. We found that dissimilarities in assemblage composition correlated more strongly with environmental than physical distances between sites. Overland and watercourse distances showed similar correlations to assemblage dissimilarity between sites, being sometimes significantly correlated with biological variation of entire insect communities. In metacommunities deconstructed by body size or dispersal mode, contrary to our expectation, passive dispersers showed a slightly stronger correlation than active dispersers to environmental differences between sites, although passive dispersers also showed a stronger correlation than active dispersers to physical distances between sites. The strength of correlation between environmental distance and biological dissimilarity also varied slightly among the body size classes. 4. After controlling for environmental differences between sites, cumulative cost distances were slightly better correlates of biological dissimilarities than overland or watercourse distances between sites. However, quantitative differences in correlation coefficients were small between different physical distances. 5. Although environmental differences typically override physical distances as determinants of the composition of stream insect assemblages, correlations between environmental distances and biological dissimilarities are typically rather weak. This undetermined variation may be attributable to dispersal processes, which may be captured using better proxies for the process. We suggest that further modifying the measurement of cost distances may be a fruitful avenue, especially if complemented by more direct natural history information on insect dispersal behaviour and distances travelled by them.

Coronary stenosis as a modifier of the effect of cold spells on the risk of sudden cardiac death: a case-crossover study in Finland.

OBJECTIVE: To test the a priori hypothesis that the association between cold spells and ischaemic sudden cardiac death (SCD) is modified by the severity of coronary stenosis. METHODS: The home coordinates of 2572 autopsy-verified cases of ischaemic SCD aged ≥35 in the Province of Oulu, Finland, were linked to 51 years of weather data. Cold spell was statistically defined for each home address as unusually cold weather pertinent to the location and time of year. We estimated the occurrence of cold spells during the hazard period (7 days preceding death) and reference periods (the same calendar days over 51 years) in a case-crossover setting applying conditional logistic regression, controlling for temporal trends and stratifying by severity of coronary stenosis. RESULTS: The association between cold spells and ischaemic SCD was stronger among patients with 75%-95% stenosis (OR 2.03; 95% CI 1.31 to 3.17), and weaker to non-existent among patients with <75% stenosis (OR 0.97; 95% CI 0.37 to 2.55) or coronary total occlusion (100% stenosis) (OR 1.01; 95% CI 0.52 to 1.96). Lack of calcium-channel blockers and statin therapy seemed to accentuate the role of stenosis during cold spells. CONCLUSIONS: We provide evidence that the association between cold spells and ischaemic SCD is modified by the severity of coronary stenosis. The findings suggest that disturbances in coronary circulation play part in the pathogenesis of SCD during cold weather.

Accessibility of tertiary hospitals in Finland: A comparison of administrative and normative catchment areas.

The determination of an appropriate catchment area for a hospital providing highly specialized (i.e. tertiary) health care is typically a trade-off between ensuring adequate client volumes and maintaining reasonable accessibility for all potential clients. This may pose considerable challenges, especially in sparsely inhabited regions. In Finland, tertiary health care is concentrated in five university hospitals, which provide services in their dedicated catchment areas. This study utilizes Geographic Information Systems (GIS), together with grid-based population data and travel-time estimates, to assess the spatial accessibility of these hospitals. The current geographical configuration of the hospitals is compared to a normative assignment, with and without capacity constraints. The aim is to define optimal catchment areas for tertiary hospitals so that their spatial accessibility is as equal as possible. The results indicate that relatively modest improvements can be achieved in accessibility by using normative assignment to determine catchment areas.

Risk of sudden cardiac death in relation to season-specific cold spells: a case-crossover study in Finland.

OBJECTIVE: To test a priori hypothesis of an association between season-specific cold spells and sudden cardiac death (SCD). METHODS: We conducted a case-crossover study of 3614 autopsy-verified cases of SCD in the Province of Oulu, Finland (1998-2011). Cold spell was statistically defined by applying an individual frequency distribution of daily temperatures at the home address during the hazard period (7 days preceding death) and 50 reference periods (same calendar days of other years) for each case using the home coordinates. Conditional logistic regression was applied to estimate ORs for the association between the occurrence of cold spells and the risk of SCD after controlling for temporal trends. RESULTS: The risk of SCD was associated with a preceding cold spell (OR 1.33; 95% CI 1.00, 1.78). A greater number of cold days preceding death increased the risk of SCD approximately 19% per day (OR 1.19; 95% CI 1.07 to 1.32). The association was strongest during autumn (OR 2.51; 95% CI 1.27 to 4.96) and winter (OR 1.70; 95% CI 1.13 to 2.55) and lowest during summer (OR 0.42; 95% CI 0.15 to 1.18) and spring (OR 0.89; 95% CI 0.45 to 1.79). The association was stronger for ischaemic (OR 1.55; 95% CI 1.12 to 2.13) than for non-ischaemic SCD (OR 0.68; 95% CI 0.32 to 1.45) verified by medicolegal autopsy. CONCLUSIONS: Our results indicate that there is an association between cold spells and SCD, that this association is strongest during autumn, when the weather event is prolonged, and with cases suffering ischaemic SCD. These findings are subsumed with potential prevention via weather forecasting, medical advice and protective behaviour.

Urbanity as a determinant of exposure to grass pollen in Helsinki Metropolitan area, Finland.

Little is known about the levels of exposure to grass pollen in urban environments. We assessed the spatio-temporal variation of grass pollen concentrations and the role of urbanity as a determinant of grass pollen exposure in the Helsinki Metropolitan area. We monitored grass pollen concentrations in 2013 at 16 sites during the peak pollen season by using rotorod-type samplers at the breathing height. The sites were in the cities of Helsinki and Espoo, Finland, and formed city-specific lines that represented urban-rural gradient. The monitoring sites were both visually and based on land use data ranked as high to low (graded 1 to 8) pollen area. The lowest grass pollen concentrations were observed in the most urban sites compared to the least urban sites (mean 3.6 vs. 6.8 grains/m3 in Helsinki; P<0.0001, and 5.2 vs. 87.5 grains/m3 in Espoo; P<0.0001). Significant differences were observed between concentrations measured in morning periods compared to afternoon periods (4.9 vs. 5.4 in Helsinki, P = 0.0186, and 21.8 vs. 67.1 in Espoo, P = 0.0004). The mean pollen concentration increased with decreasing urbanity both in Helsinki (0.59 grains/m3 per urbanity rank, 95% CI 0.25-0.93) and Espoo (8.42, 6.23-10.61). Pollen concentrations were highest in the afternoons and they were related to the ambient temperature. Urbanity was a strong and significant determinant of pollen exposure in two Finnish cities. Pollen exposure can periodically reach such high levels even in the most urban environments that can cause allergic reactions among individuals with allergies.

Cold spells and ischaemic sudden cardiac death: effect modification by prior diagnosis of ischaemic heart disease and cardioprotective medication.

Sudden cardiac death (SCD) is the leading cause of death. The current paradigm in SCD requires the presence of an abnormal myocardial substrate and an internal or external transient factor that triggers cardiac arrest. Based on prior mechanistic evidence, we hypothesized that an unusually cold weather event (a cold spell) could act as an external factor triggering SCD. We tested potential effect modification of prior diagnoses and select pharmacological agents disrupting pathological pathways between cold exposure and death. The home coordinates of 2572 autopsy-verified cases of ischaemic SCD aged ≥35 in the Province of Oulu, Finland, were linked to 51 years of home-specific weather data. Based on conditional logistic regression, an increased risk of ischaemic SCD associated with a cold spell preceding death (OR 1.49; 95% CI: 1.06-2.09). Cases without a prior diagnosis of ischaemic heart disease seemed more susceptible to the effects of cold spells (OR 1.70; 95% CI: 1.13-2.56) than cases who had been diagnosed during lifetime (OR 1.14; 95% CI: 0.61-2.10). The use of aspirin, ß-blockers, and/or nitrates, independently and in combinations decreased the risk of ischaemic SCD during cold spells. The findings open up new lines of research in mitigating the adverse health effects of weather.

Fine-Scale Exposure to Allergenic Pollen in the Urban Environment: Evaluation of Land Use Regression Approach.

BACKGROUND: Despite the recent developments in physically and chemically based analysis of atmospheric particles, no models exist for resolving the spatial variability of pollen concentration at urban scale. OBJECTIVES: We developed a land use regression (LUR) approach for predicting spatial fine-scale allergenic pollen concentrations in the Helsinki metropolitan area, Finland, and evaluated the performance of the models against available empirical data. METHODS: We used grass pollen data monitored at 16 sites in an urban area during the peak pollen season and geospatial environmental data. The main statistical method was generalized linear model (GLM). RESULTS: GLM-based LURs explained 79% of the spatial variation in the grass pollen data based on all samples, and 47% of the variation when samples from two sites with very high concentrations were excluded. In model evaluation, prediction errors ranged from 6% to 26% of the observed range of grass pollen concentrations. Our findings support the use of geospatial data-based statistical models to predict the spatial variation of allergenic grass pollen concentrations at intra-urban scales. A remote sensing-based vegetation index was the strongest predictor of pollen concentrations for exposure assessments at local scales. CONCLUSIONS: The LUR approach provides new opportunities to estimate the relations between environmental determinants and allergenic pollen concentration in human-modified environments at fine spatial scales. This approach could potentially be applied to estimate retrospectively pollen concentrations to be used for long-term exposure assessments. CITATION: Hjort J, Hugg TT, Antikainen H, Rusanen J, Sofiev M, Kukkonen J, Jaakkola MS, Jaakkola JJ. 2016. Fine-scale exposure to allergenic pollen in the urban environment: evaluation of land use regression approach. Environ Health Perspect 124:619-626; http://dx.doi.org/10.1289/ehp.1509761.

Short-term outcome and differences between rural and urban trauma patients treated by mobile intensive care units in Northern Finland: a retrospective analysis.

BACKGROUND: Emergency medical services are an important part of trauma care, but data comparing urban and rural areas is needed. We compared 30-day mortality and length of intensive care unit (ICU) stay for trauma patients injured in rural and urban municipalities and collected basic data on trauma care in Northern Finland. METHODS: We examined data from all trauma patients treated by the Finnish Helicopter Emergency Medical Services in 2012 and 2013. Only patients surviving to hospital were included in the analysis but all pre-hospital deaths were recorded. All data was retrieved from the national Helicopter Emergency Medical Services database, medical records, and the Finnish Causes of Death Registry. Patients were defined as urban or rural depending on the type of municipality where the injury occurred. RESULTS: A total of 472 patients were included. Age and Injury Severity Score did not differ between rural and urban patients. The pre-hospital time intervals and distances to trauma centers were longer for rural patients and a larger proportion of urban patients had intentional injuries (23.5% vs. 9.3%, P <0.001). The 30-day mortality for severely injured patients (Injury Severity Score >15) was 23.9% in urban and 13.3% in rural municipalities. In the multivariate regression analysis the odds ratio (OR) for 30-day mortality was 2.8 (95% confidence interval 1.0 to 7.9, P = 0.05) in urban municipalities. There was no difference in the length of ICU stay or scores. Twenty patients died on scene or during transportation and 56 missions were aborted because of pre-hospital death. CONCLUSIONS: The severely injured urban trauma patients had a trend toward higher 30-day mortality compared with patients injured in rural areas but the length of ICU stay was similar. However, more pre-hospital deaths occurred in rural municipalities. The time before mobile ICU arrival appears to be critical for trauma patients' survival, especially in rural areas.